Ed Miliband is rapidly emerging as a scourge of the right-wing press. His bitter complaint to the Daily Mail about its attack on his father follows his willingness to go to war with Rupert Murdoch over phone-hacking.

And it underlines just why he has been eager to forge a new system of independent press regulation, in opposition to the majority of newspaper publishers, as part of the post-Leveson settlement.

Politicians get so used to personalised press criticism that they usually shrug and accept, as Miliband observes, that "it comes with the territory".

But he was unable to turn the other cheek when he read the Mail's article, which claimed that his father, Ralph, was a "man who hated Britain".

As Patrick Wintour reports, Miliband argued his case for a right of reply with such force that the Mail's editor, Paul Dacre, was forced to give him space.

It came at a price. Dacre could not allow Miliband's article to appear without reinforcing the paper's prejudices. So he surrounded Miliband's defence of his father with two more articles, one repeating most of the original piece and another, an editorial, stating: "We stand by every word of what we published."

Even so, I cannot recall the Mail ever running an article that contained such trenchant criticism of its journalism. At the heart of Miliband's piece are these key paragraphs:

"Britain has always benefited from a free press. Those freedoms should be treasured. They are vital for our democracy. Journalists need to hold politicians like me to account — none of us should be given an easy ride — and I look forward to a robust 19 months between now and the general election.

But what appeared in the Daily Mail on Saturday was of a different order all together. I know they say 'you can't libel the dead', but you can smear them.

Fierce debate about politics does not justify character assassination of my father, questioning the patriotism of a man who risked his life for our country in world war II, or publishing a picture of his gravestone with a tasteless pun about him being a 'grave socialist.'"

Miliband, barely hiding his personal hurt, manages to show how "a free press" can be subverted by intense political bias.

Elsewhere he shows how the Mail constructed its assault on the memory of his father by relying on "a single diary entry" written by his father as a 17-year-old fugitive from Nazi oppression.

While prepared himself to take the usual brickbats Labour leaders can expect from the Mail, he writes: "My Dad is a different matter. He died in 1994. I loved him and he loved Britain. And there is no credible argument in the article or evidence from his life which can remotely justify the lurid headline [The man who hated Britain]."

He accuses the Mail of brushing over his father's wartime years in the navy and his contribution to the fight against a regime that murdered his Jewish relatives.

In accepting that his father had "strongly left-wing views" he points out that, despite them, he viewed Britain as "a source of hope and comfort for him, not hatred… he loved Britain for the security it offered his family and the gentle decency of our nation."

Miliband's article destroyed the basis for the Mail's Saturday essay by Geoffrey Levy. But the Mail was having none of it.

Its editorial is a disingenuous attempt to appear surprised at Miliband having dared to complain: "Red Ed's in a strop with the Mail… he has stamped his feet and demanded a right of reply."

It calls Miliband's response "tetchy and menacing" and affects to overlook the key point of his argument - that the attack relied on a single entry in a 17-year-old's diary - by simply repeating it as some kind of justification for its hatchet job.

The Mail then charts Ralph Miliband's so-called sins for his supposed "hatred" for Britain's "values, traditions and institutions" and his opposition to the Falklands war.

At one point, I thought I was reading a piece from the Daily Express in the lead-up to the 1945 general election with its references to "extremist left-winger Harold Laski" and Miliband's friendship with "fellow Marxist" Eric Hobsbawm.

Then, despite a denial, comes the attempt to link father to son:

"We do not maintain, like the jealous god of Deuteronomy, that the iniquity of the fathers should be visited on the sons.

But when a son with prime ministerial ambitions swallows his father's teachings, as the younger Miliband appears to have done, the case is different."

It continues by arguing that "his son's own Marxist values can be seen all too clearly in his plans for state seizures of private land held by builders and for fixing energy prices by government diktat."

And finally comes another message ahead of this month's landmark decision by the privy council on the future of press regulation:

"More chillingly, the father's disdain for freedom of expression can be seen in his son's determination to place the British press under statutory control…

If he crushes the freedom of the press, no doubt his father will be proud of him from beyond the grave, where he lies 12 yards from the remains of Karl Marx."

Miliband now knows well enough that, in this secular world, "the jealous god of Deuteronomy" is not the problem. It is the wrathful god of the Daily Mail, Paul Dacre, who seeks to control his, and our, destiny.

The Guardian has published an extensive critique of the Daily Mail and its reporting of Labour, press regulation and the Snowden leaks. We invited Mail readers to join in that debate. Paul Dacre, editor-in-chief, asked for the opportunity to comment. Here is his contribution